Price computer

ABSTRACT

An improved price increment computer is disclosed that is used in a price computer for gasoline or fuel dispensing pumps wherein a blend of gasolines is dispensed. The improved price increment computer includes an input shaft that rotates in response to the total volume of blended fluid being dispensed and an output shaft that rotates at speeds proportional to the speed of the input shaft. An idler mechanism is provided that selectively and operably connects portions of the input and output shafts to provide the desired ratio of rotation therebetween. A selector mechanism that is rotated by the operator of the dispenser includes a plurality of cams, each of which engages a preselected portion of the idler mechanism to provide the desired output rotation depending on the price of the blend selected. The improved price increment computer is constructed so that the selector mechanism can be quickly and easily removed from the price increment computer to provide for the insertion, removal or repositioning of the cams whereby price changes and variations can be quickly and easily accomplished.

[15] 3,655,944 [451 Apr. 11,1972

United States'Patent Nelson ayer, Thomas P. Hubbard, Jr., Daniel ajesko, Roy L. Van Winkle, William E.

ABSTRACT ly accomplished.

8 Claims, 9 Drawing Figures PATENTEDIPII II |972' 3.655.944

SHEET 1 F 4 24 Io 2O 38 36 22 f BABE HIGH I f`- VALVE VALVE 50 48W BAsE HIGH T" GEAR Box D'FFERENT'AL AGEAR Box GG PRICE COUNTER f fG4 PRICE INCREMENT COMPUTER DIFFERENTIAL G'o f n I BAsE PRICE COMPUTER f5B 52 G2j T DIFFERENTIAL ToTAL GALLoNs I* COUNTER fI8 Gef BASE METER MGE', J

- BABE PUMP HIGH PUMP q 2B '4 '2j I-TIG I 26 INVENTOR ATTORNEY PATENTEDAPRH |972 3,655,944

SHEET 2 F 4 F'IG. 2

INVENTOR DANA W. N ELSON l?, Mm

ATTORNEY PATENTEDAPR 1l |912 n 3,555,944

IOO

INVENTOR DANA W. NELSON A TTORNE Y PRICE COMPUTER BACKGROUND OF THE INVENTION Fuel blending dispensers have been in fairly extensive use in the industry since the late 1950's. Generally, such blending devices fall into two basic categories. The first category includes proportional blenders" in which total price of the blend is directly proportional to the quantity of low octane gasoline and high octane gasoline blended. The other category, that is, the incremental blenders, compute the cost of the blended liquid based on the total volume delivered multiplied by the price of the low octane gasoline plus an add on or artificially inserted additional price that is known as the incremental price.

One apparatus used in the past to accomplish the incremental price add-on has consisted of an input shaft driven by the total volume output mechanism, an output shaft that rotates in a selected proportional ratio to the input shaft, a plurality of gear sets mounted on the input and output shafts, idler gears that are movable into engagement with the sets of the input and output gears to provide the mechanical driving connection therebetween, and a selector mechanism that includes a plurality of cams that are adapted to be positioned to move the idler gears into engagement with the input and output gears at a preselected position of the selector mechanism. The cams in the selector mechanism are movable into position adjacent various ones of the idler gears so that a selected blend can have a predetermined price increment added to the price of the low octane fuel for the total blended fuel delivered. In the past it has been normal practice that themore high octane gasoline in the blended liquid, the higher the total cost and, thus, the cams for each blend could be simply positioned along the selector mechanism to provide an increasing price for each blend selected. y

More recently, and particularly with the advent of lowleaded or non-leaded gasolines which will now be the low or base liquid, the price of the base liquid may lbe above the price of a blend of the base liquid with a small amount of the high octane gasoline. In some instances, the base liquid may be priced at the same price as one or more of the blended fuels. Thus, it is now necessary to provide an incremental computer with the capability of computing a level or down dip pricing arrangement in contrast to the previously known propor tionally increasing pricing arrangement.

In addition, the previously existing price increment units utilized cams that were constructed from a plastic material and, thus, could be rather easily cut and removed from the selector mechanism if it were decided that la particular blend was no longer to be marketed. Considerable difficulty was encountered and much time was consumed in replacing a cam on the selector mechanism. In fact, the price increment computer had to be removed from the blend computer and then disassembled with its many shafts, gears, etc. in order to remove the selector shaft and add to, or rearrange the actuating sequence of the cams placed thereon.

SUMMARY- OF THE INVENTION This invention provides an improved price computer or price increment computer for use in apparatus for computing and indicating the price of a blended liquid that includes: rotatable input means adapted for connection with the output of the volume totalizer means; rotatable output means adapted for connection with the price indicator means; idler means selectively engageable with the input and output means whereby the output means rotates at a selected speed proportional to the input means rotation; selector means engageable with the idler means to move the idler means into engagement with the input and output means. The computer also includes: a first end assembly having a first member operably supporting one end of the input, output and idler means and a second member releasably connected to the first member operably supporting one end of the selector means; a second end assembly having a first member operably supporting the input,

output and idler means and a second member removably positioned on the first member operably supporting the selector means; and, the second members of the end assemblies easily removable to provide access to the selector means whereby the selector means can be quickly arranged in the desired arrangement to produce selected ratios between the input and output means.

A main object of the invention is to provide an improved price increment computer wherein the selector mechanism employed therein can be quickly and easily removed from the computer for adjustment, removal or replacement of the cams without requiring the disassembly of the entire price increment computer.

Another object of the invention is to provide a price increment computer wherein any desired pricing arrangement for blended fuels can be quickly and easily attained.

The foregoing and additional objects and advantages of the invention will become more apparent as the following detailed description is read in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS.

FIG. l is a schematic view of a fuel blending system.

FIG. 2 is a pictorial view illustrating the details of construction of a price increment computer constructed in accordance with the invention.

FIG. 3 is an end view, partially in cross section, of one end assembly utilized in the price increment computer of FIG. 2.

FIG. 4 is an end view, partially in cross section, of the other end assembly utilized in the price increment computer of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing and to FIG. l in particular, shown therein'and generally designated by the reference character 10 is a blending pump system. The blending pump system l0 includes a base fuel pump 12 connected by an inlet line 14 to a source of base or regular gasoline. A conduit 16 connects the outlet of the pump l2 with a meter 18 that has its outlet connected with a fuel metering valve 20 by a conduit 22. The outlet from the valve 20 is connected by a conduit 24 with a hose, nozzle, etc. (not shown).

Similarly, a high fuel pump 26 is connected by an inlet conduit 28 with a source of high fuel (not shown). The output of the pump 26 is connected by a conduit 30 with a fuel meter 32 that is connected by a conduit 34 with a high fuel metering valve 36. The outlet from the high metering valve 36 is also connected with the hose, nozzle, etc. (not shown) by a conduit 38.

Output 40 from the base meter 18 is representative of the volume of fuel flowing through the meter 18. The output 40 is connected to a gear box 42 that has its output connected with a differential 44. An output 46 from the high meter 32 is connected with a high gear box 48 and its output is also connected with the differential 44.

Output 50 from the differential 44 is representative of the difference between the outputs from the base gear box 42 and the high gear box 48 and is connected with the base metering valve and the high metering valve 20 and 36, respectively. The arrangement is such that is the selected blend is not being dispensed, the output 50 causes a repositioning of the valves 20 and 36 so that the proper blend is dispensed.

The outputs 40 and 46 from the meters 18 and 32, respectively, are also fed into an adding differential 52. The adding differential 52 has a first output 54 that is connected to a total gallons counter 56 that indicates on the face of the blending pump (not shown) the total gallons of blended fuel delivered.

A second output 58 from the adding differential 52 is connected into a price increment computer 60, which will be described hereinafter, and a base price computer 62.

The outputs from both the price increment computer 60 and the base price computer 62 are connected to an additional adding differential 64'whose output represents the total price of the blended fuel being delivered. The output from the differential 64 is fed into a price counter 66 that will indicate on the face of the blending pump the total price of the blended fuel being delivered.

As previously mentioned, in the incremental type blending computers, the price of the low or base fuel is applied to the total volume of fluid delivered and this can be easily seen in FIG. 1 since the output 58 from the differential 52 represents the total volume of fluid flowing through the system and this output 5.8 is fed into the base price computer 62 wherein the proper factors are applied so that the output from the computer 62 is representative of the cost of the total volume if only low or base fuel were being dispensed by the system. The add-on or price increment, whichresults from the high fuel being added, is computed by the price increment computer 60. The details of construction of the price increment computer 60 are shown in the remaining figures of the drawing.

Referring to FIG. 2, the price increment computer 60 is shown as assembled and includes a first end plate assembly 70, a second end plate assembly 72 spaced from the end plate assembly 70, an input shaft 74, an output shaft 76, an idler assembly 78, and a selector assembly 80. The input shaft 74 of the price increment computer 60 will be operably connected with the output 58 from the differential 52 and the output shaft 76 will be operably connected with the price counter 66 through the differential 64. 'l

As clearly shown in FIG. 2, the input shaft 74 and output shaft 76 are provided with a plurality of sets of gears having varying numbers of teeth. Although it is not clear in FIG. 2, the individual gears of the gear sets are not in mesh and, thus, rotation of the input shaft 74 does not cause rotation of the output shaft 76 except through the idler mechanism 78 as will be explained.

The price increment computer 60 includes, for each of the gear sets on the inputand output shafts 74 and 76, respectively, an idler arm 82 and idler gear 84 as shown in FIG. 7. The idler arms 82 are pivotally supported on an idler shaft 86. To cause the proportional rotation of the output shaft 76, one of the idler arms 82 is swung toward one of the gear sets bringing the idler gear 84 carried thereby into mesh with the input and output gears of one gear set. The output shaft 76 can rotate at any one of a plurality of selected speeds for the same speed of the input shaft 76 depending upon which idler gear 84 and gear set is brought into engagement. It will be noted, that the input shaft 74 and the output shaft 76 are journaled in the endplate assemblies 70 and 72. The idler shaft 86 is supported by both the end plate assemblies 70 and 72 and may be journaled therein if desired.

The selector assembly 80 includes a large spur gear 88 that is arranged to be driven from the exterior ofthe blending pump (not shown) by the operator. In the preferred form of the invention, the spur gear 88 is connected by means of an idler gear and an index gear (not shown) to the external selector which includes .a plurality of finite positions that correspond to'rotative positions of the gear 88. l

The gear 88 is fixed to and rotatable with a splined selector shaft 90 that has one end journaled in a removable support member 92 of the end assembly 72 and a removable support member 94 of the end assembly 70. The support members 92 and 94 are clearly shown in FIGS. 3 and 4.

In FIG. 3, it can be seen that the support member 9'2 is connected to the remainder of the end assembly 72 by`means of a screw 96. As shown in FIG. 4, the support member 94 fits into a recess 98 formed in the end assembly 70 and has an elongated body portion 100 that fits closely into a groove formed by flanges 102 and 104 located on the end assembly 70 to securely retain the member 94 therein.

Referring the FIGS. 5 and 6, it can be seen that the elongated portion 100 extends generally parallel to the splined selector shaft and has its opposite end 106 fastened to the support member 92 by a screw 108.

A plurality of cams 110 are located on the splined selector shaft 90. Each of the cams 110 includes a splined opening (See FIG. 7) that extends therethrough for receiving the splined selector shaft 90 so that the cams 110 are rotatable therewith. As may also be seen most clearly in FIG. 7, the cams 110 are provided with a lobe 112 that is disposed eccentrically to the shaft 90 and is adapted to engage one of the idler arms 82 when the selector shaft 90 is rotated to the proper position. The lobe 112 moves the idler gear 84 into mesh with the adjacent input and output gear set.

A plurality of cam positioning members 114 are mounted on the elongated portion of the support member 94. In FIG. 6, it can be seen that each of the positioning members 114 is bifurcated and includes tines 116 and 118 that are located on each side of one cam so that the cam is retained at spaced intervals and at a selected position along the splined selector shaft 90. The cam positioning members 114 are constructed from a spring steel material and include a protuberance (not shown) that is located in one of several spaced holes located along the elongated portion 100 as shown in FIG. 2. The holes 120 are so that when the cam positioning members 114 are positioned therein, each cam 110 is positioned adjacent a selected one of the idler arms 82.

l FIG. 8 illustrates another form of cam 121 that can be utilized on the splined selector shaft 90. The cam 121 has a pair of spaced lobe's 122 and 124. As arranged, the cam 121, when rotated by the selector shaft 90, moves the adjacent idler gear 84 into engagement with the input and output gear set in two different positions of the selector shaft 90. For example, the cam 121 positions the idler gear 84 in mesh in a first position, skips the second position, the reengages the idler gear 84 in a third position. Thus, the first and third position fuel blends will be delivered at the same price while an intervening blend in the second position will be delivered at a different price that will be determined by another cam carried by the selector shaft 90. As a result, the first position blend could be priced at 29.9 cents per gallon and the third position price at 29.9 cents per gallon while the second position blend could be priced at either a higher or lower value as desired.

FIG. 9 illustrates still another embodiment of cam 130 that may also be utilized with the splined selector shaft 90. The cam has a single large lobe 132 that is sufficiently wide to move the selected idler gear 84 into engagement with the input and output gear set in successive positions of the selector shaft. Thus, with the cam 130, thefirst and second position blends will be priced at the same value.

OPERATION OF TI-IE PREFERRED EMBODIMENT.

The operation of the blending system 10 and the price increment computer 60 has been previously discussed in some detail and, therefore, the following operational description will be limited to the quick-change capabilities of the price increment computer 60. For the purpose of this discussion, primary reference will be made to FIGS, 2, 5, and 6.

As shown therein, cam positioning members 114 are located on the elongated portion 100 to retain the cams 110 adjacent the desired idler arms 82. If it is desired to change the price of a particular blend, but it is not necessary to remove a cam 110 or replace a cam 110 with another cam type, such as a c am 121 or 130, itis only necessary to exert a force on the cam positioning member 114 andslide it along the elongated portion 100 until the cam 1 10 is located adjacent the idler arm 82 that will result in the desired ratio of shaft speeds.

However, if it is desired to remove a cam 110 or replace it with afcam 121 or 130, the selector assembly 80 must be removed from the price increment computer 60. The removal is accomplished by unscrewing the fastener 96 and pulling the selector assembly 80 in a direction parallel to the axis of the splined shaft 90. Such movement removes the member 94 from the opening 98 in the end assembly 70. As removed, the selector assembly 80 will be in the configuration illustrated in FIG. 5. It should be pointed out, that the cams 110 will not necessarily be positioned as illustrated in FIG. 5 since they will remain in the preselected positions as retained by the cam positioning members 114.

To disassemble the selector assembly 80 so that the cams 110 can be removed therefrom, the screw 108 is removed from the member 92 and the splined shaft 90 and gear 88 are slipped out of the member 94 so that the selector assembly 80 is now in the configuration as generally illustrated in FIG. 6. Any number of the cams 110 can be slipped off the end of the spline shaft 90.

Either or both of the cams 121 and 130 as illustrated in FIGS. 8 and 9 can be inserted on the spline shaft 90 in the desired positions along with the relocation of the desired number of cams 110. While the selector assembly 80 is disassembled, cam positioning members 114 can be repositioned to the desired locations since the holes 120 will locate the positioning members 114 and cams 110, 121 or 130 will be positioned adjacent the selected ones of the idler arms 82. This can be accomplished since the holes 120 positively locate the cam positioning members 114 in alignment with the idler arms Assembly of the selector assembly 80 is accomplished by reinserting the splined shaft 90 in the member 94 and connecting the elongated portion 100 of the member 94 with the member 92 by means of the screw 108. The assembled selector assembly 80 is then placed in the price increment computer 60 by inserting the member 94 in the opening 98 in the end plate assembly 70 and again attaching the member 92 to the end plate assembly 72 by means of the threaded screw 96.

As will be appreciated from the foregoing, the replacement and/or repositioning of the cams can be quickly and easily accomplished in the price increment computer 60. In the prior art price increment computers, it has been necessary to entirely remove the end plate assemblies, completely dsassembling the price increment computer in order to accomplish the replacement of the cams, As can be appreciated from viewing FIG. 2, the rather large number of gears, shafts, etc. that are involved would considerably extend the time and difficulty involved in changing the pricing arrangement as compared to the improved price increment computer 60 described in detail hereinbefore.

Although not illustrated, the entire blending computer is a relatively complex structure and the price increment computer forms only a small portion thereof. Normally of price increment computer is located in a relatively difficult area to service and the necessity for removing the price increment computer from the entire blend computer unduly complicates the desired pricing changes in the older price increment units. With the improved increment computer 60, it is not necessary to remove the price increment computer from the blending computer, but simply to remove the selector assembly 80 therefrom as previously described herein.

The embodiment described in detail hereinbefore is presented by way of example only and it will be understood that many changes and modifications can be made thereto without departing from the spirit or scope of the invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In apparatus for computing and indicating the price of a blended liquid, said apparatus including a meter for each liquid whose output represents the volume of liquid flowing therethrough, totalizing means connected with the meter outputs having an output representing the total volume of blended liquid, a first price computer connected with the 6 totalizing means, and price indicator means connected with the first price computer, the improvement comprizing a second price computer connected with the totalizing means and with the price indicator means and including:

an input shaft operably connectable with the output of the totalizer means;

an output shaft operably connectable with the price indicator means;

a plurality of pairs of gears of varying ratio carried on said shafts in aligned relationship;

idler means engageable with said gears whereby said output shaft rotates at a selected speed proportional to the speed of said input shaft;

a selector shaft having a plurality of cams mounted thereon for engagement with said idler means to move said idler means into engagement with a selected pair of said gears;

a first end assembly having a first member journaling one end of said input and output shafts and supporting said idler means and a second member releasably connected to said first member journaling one end of said selector shaft;

a second end assembly having a first member journaling the other ends of said input and output shafts and supporting said idler means and a second member removably positioned on said first member journaling said selector shaft; and,

said second members of said end assemblies being easily removable to provide access to said selector shaft and cams whereby said cams can be quickly removed, replaced and repositioned on said selector shaft.

2. The apparatus of claim 1 wherein said second member of said second end assembly includes:

a first end portion journaling said selector shaft;

a second end portion releasably connected to said second member of said first end assembly; and,

an elongated body portion between said first and second end portions extending generally parallel to said selector shaft and having a plurality of cam positioning members located thereon, said positioning members being movable to selected positions along said body portion and each being bifurcated to encompass one cam whereby said cams are retained in selected positions by said positioning members. Y

3. The apparatus of claim 2 wherein:

said selector shaft includes a plurality of splines extending i generally along its length; and

each said cam 'has a splined opening extending therethrough for receiving said selector shaft and each cam has at least one lobe portion arranged eccentrically with respect to said selector shaft for engaging said idler means, said splined'opening and selector shaft splines permitting the location of said cams at any one of a plurality of positions for engaging said idler means at a preselected position along said selector shaft.

4. The apparatus of claim 3 wherein:

said selector shaft is rotatable through a preselected number of positions wherein a respective one of said cam lobe portions engages said idler means; and,

wherein at least one said lobe portion engages said idler means in at least two of said preselected rotational positions of said selector shaft.

5. In apparatus for computingand indicating the price of a blended liquid, said apparatus including a meter for each liquid whose output represents the volume of liquid flowing therethrough, totalizing means connected with the meter outputs having an output representing the total volume of blended liquid, a first price computer connected with the totalizing means, and price indicator means connected with the first price computer, the improvement comprizing a second price computer connected with the totalizing means and with the price indicator means and including:

rotatable input means adapted for connection with the output of the totalizer means;

rotatable output means adapted for connection with the price indicator means;

idler means selectively engageable with said input sand output means whereby said output means rotates at a selected speed proportional to said input means rotation;

selector means engageable with said idler means to engage said idler means with said input and output means;

a first end assembly having a first member operably supporting one end of said input, output and idler means and a second member releasably connected to said first member operably supporting one end of said selector means;

a second end assembly having a first member operably sup porting said input, output and idler means and a second member removably positioned on said first member operably supporting said selector means; and,

said second members of said end assemblies being easily removable to provide access to said selector means whereby said selector means can be quickly arranged for engagement with selected portions of said idler means to effect the desired ratio between said input and output means.

6. The apparatus of claim wherein said selector means includes:

a splined shaft having one end journaled in the second member of said first end assembly and the other end journaled in the second member of said second end assembly; and,

a plurality of cams slidably positioned on said selector shaft and rotatable therewith, said camsreach have a lobe portion eccentric to said selector shaft for engaging said idler means.

7. The apparatus of claim 6 wherein said selector shaft is rotatable through a predetermined number of positions and the lobe portion of at least one of said cams being engageable with said idler means in more than one of said predetermined number of positions.

8. The apparatus of claim 7 wherein:

said second member of said second end assembly includes a first end portion journaling said selector shaft, a second end portion releasably connected to the second member of said first end assembly, and an elongated body portion extending generally parallel to said selector shaft between said ends; and,

a plurality of bifurcated cam positioning members having a tine positioned on each side of each of said cams and located on said elongated body portion, said cam positioning member being selectively movable on said body portion to locate and retain each said cam adjacent a desired portion of said idler means. 

1. In apparatus for computing and indicating the price of a blended liquid, said apparatus including a meter for each liquid whose output represents the volume of liquid flowing therethrough, totalizing means connected with the meter outputs having an output representing the total volume of blended liquid, a first price computer connected with the totalizing means, and price indicator means connected with the first price computer, the improvement comprizing a second price computer connected with the totalizing means and with the price indicator means and including: an input shaft operably connectable with the output of the totalizer means; an output shaft operably connectable with the price indicator means; a plurality of pairs of gears of varying ratio carried on said shafts in aligned relationship; idler means engageable with said gears whereby said output shaft rotates at a selected speed proportional to the speed of said input shaft; a selector shaft having a plurality of cams mounted thereon for engagement with said idler means to move said idler means into engagement with a selected pair of said gears; a first end assembly having a first member journaling one end of said input and output shafts and supporting said idler means and a second member releasably connected to said first member journaling one end of said selector shaft; a second end assembly having a first member journaling the other ends of said input and output shafts and supporting said idler means and a second member removably positioned on said first member journaling said selector shaft; and, said second members of said end assemblies being easily removable to provide access to said selector shaft and cams whereby said cams can be quickly removed, replaced and repositioned on said selector shaft.
 2. The apparatus of claim 1 wherein said second member of said second end assembly includes: a first end portion journaling said selector shafT; a second end portion releasably connected to said second member of said first end assembly; and, an elongated body portion between said first and second end portions extending generally parallel to said selector shaft and having a plurality of cam positioning members located thereon, said positioning members being movable to selected positions along said body portion and each being bifurcated to encompass one cam whereby said cams are retained in selected positions by said positioning members.
 3. The apparatus of claim 2 wherein: said selector shaft includes a plurality of splines extending generally along its length; and each said cam has a splined opening extending therethrough for receiving said selector shaft and each cam has at least one lobe portion arranged eccentrically with respect to said selector shaft for engaging said idler means, said splined opening and selector shaft splines permitting the location of said cams at any one of a plurality of positions for engaging said idler means at a preselected position along said selector shaft.
 4. The apparatus of claim 3 wherein: said selector shaft is rotatable through a preselected number of positions wherein a respective one of said cam lobe portions engages said idler means; and, wherein at least one said lobe portion engages said idler means in at least two of said preselected rotational positions of said selector shaft.
 5. In apparatus for computing and indicating the price of a blended liquid, said apparatus including a meter for each liquid whose output represents the volume of liquid flowing therethrough, totalizing means connected with the meter outputs having an output representing the total volume of blended liquid, a first price computer connected with the totalizing means, and price indicator means connected with the first price computer, the improvement comprizing a second price computer connected with the totalizing means and with the price indicator means and including: rotatable input means adapted for connection with the output of the totalizer means; rotatable output means adapted for connection with the price indicator means; idler means selectively engageable with said input sand output means whereby said output means rotates at a selected speed proportional to said input means rotation; selector means engageable with said idler means to engage said idler means with said input and output means; a first end assembly having a first member operably supporting one end of said input, output and idler means and a second member releasably connected to said first member operably supporting one end of said selector means; a second end assembly having a first member operably supporting said input, output and idler means and a second member removably positioned on said first member operably supporting said selector means; and, said second members of said end assemblies being easily removable to provide access to said selector means whereby said selector means can be quickly arranged for engagement with selected portions of said idler means to effect the desired ratio between said input and output means.
 6. The apparatus of claim 5 wherein said selector means includes: a splined shaft having one end journaled in the second member of said first end assembly and the other end journaled in the second member of said second end assembly; and, a plurality of cams slidably positioned on said selector shaft and rotatable therewith, said cams each have a lobe portion eccentric to said selector shaft for engaging said idler means.
 7. The apparatus of claim 6 wherein said selector shaft is rotatable through a predetermined number of positions and the lobe portion of at least one of said cams being engageable with said idler means in more than one of said predetermined number of positions.
 8. The apparatus of claim 7 wherein: said second member of said second end assembly includes a first end portion journaling said selector shaft, a second end portion releasably connected to the second member of said first end assembly, and an elongated body portion extending generally parallel to said selector shaft between said ends; and, a plurality of bifurcated cam positioning members having a tine positioned on each side of each of said cams and located on said elongated body portion, said cam positioning member being selectively movable on said body portion to locate and retain each said cam adjacent a desired portion of said idler means. 